Hepatitis E Virus (HEV) is a single-stranded, positive-sense RNA virus classified in the family Hepeviridae and the sole member of the genus Hepevirus, of which mammalian HEV and avian HEV are the two major known species. Dalton et al., Lancet Infect. Dis. 8:698-709, 2008; Baylis et al., J. Clin. Microbiol. 49:1234-1239, 2011. Mammalian HEV, having a reservoir in pigs and potentially other mammals, is a major cause of acute hepatitis in humans. See Dalton et al., supra. The virus is transmitted primarily via the fecal-oral route and is associated with sporadic infections and epidemics in developing countries, particularly in areas with poor sanitation and weak public health infrastructures. In developed countries, HEV infection has been considered rare, occurring primarily in individuals infected while traveling to regions where the virus is endemic. Recently, however, autochthonous infections are being reported more frequently in developed regions, including North America, Europe, Japan, New Zealand, and Australia. Autochthonous hepatitis E in developed countries is, therefore, more common than previously recognized, and may be more common than hepatitis A. Dalton et al., Lancet Infect. Dis. 8:698-709, 2008.
Four major genotypes of HEV are known to cause infections in humans. Baylis et al., supra. Clinical features of HEV infection can include mild to severe hepatitis as well as subacute liver failure. See, e.g., Pina et al., J. Hepatol. 33:826-833, 2000; Sainokami et al., J. Gastroenterol. 39:640-648, 2004; Tsang et al., Clin. Infect. Dis. 30:618-619, 2000; Widdowson et al., Clin. Infect. Dis. 36:29-33, 2003; Dalton et al., Eur. J. Gastroenterol. Hepatol. 20:784-790, 2008. HEV infection has a poor prognosis in pregnant women, as well as individuals having pre-existing chronic liver disease. See Borkakoti et al., J. Med. Virol. 85:620-626, 2013; Baylis et al., supra. Diagnostic testing for HEV in patients with hepatitis symptoms is important, particularly for patients in which other causes of acute hepatitis have been excluded. See Baylis et al., supra; Waar et al., J. Clin. Virol. 33:145-149, 2005.
Accordingly, there is a need for compositions, kits, and methods for detecting the presence or absence of HEV in a specimen with high specificity and sensitivity. Such compositions, kits, and methods would be particularly useful for the diagnosis of HEV, for the screening and/or monitoring of the presence of HEV in a blood or plasma donation, or for monitoring a patient's response to treatment. The present invention meets these and other needs.